A transformation he began in April — shortly after the Green Bay Packers drafted Kevin King and safety Josh Jones in the second round — replaced one of the bigger and slower inside linebackers with a smaller and quicker safety in the nickel defense. It was the basketball equivalent of a four-guard lineup, and the Packers called it the nitro package.

But the ship was taking on water as the winless Cincinnati Bengals clung to a fourth-quarter lead.

“That was the biggest thing,” defensive tackle Ricky Jean Francois said. “I know a lot of people wanted to see what our defensive line would look like without Mike.”

Mike, of course, is defensive end Mike Daniels, the Packers’ best defensive player who was felled by a hamstring injury last week and unable to play against the Bengals. Capers was also without his best edge setter in outside linebacker Nick Perry and his biggest hitter in safety Kentrell Brice.

And so it was when the biggest test of the nitro defense arrived with nine minutes and 43 seconds remaining in the fourth quarter, the Bengals assuming possession at their own 9-yard line. They would pound the ball to win the game unless the Packers could stop them.

“We battled out there and made the plays when we needed to,” outside linebacker Clay Matthews said, “especially that second half.”

The Packers erased a two-score deficit for a thrilling overtime victory, 27-24, on a field goal by kicker Mason Crosby. But while the final score suggests the Packers halted the Bengals when it mattered most, the reality is that Sunday’s game called into question the veracity of the nitro defense against the run for the second consecutive week.

Seven days after the Falcons had run through them for 126 yards on 25 carries, the Bengals pounded forward for 110 yards of their own. Rookie tailback Joe Mixon, the divisive second-round pick from Oklahoma who visited the Packers during the pre-draft process, churned out 101 total yards in a performance that foreshadowed his potential for greatness. And were it not for an untimely slip in the closing moments, Mixon might have exited Lambeau Field with a win.

“Don’t get me wrong, we got them today,” Jean Francois said, “but they got us, too. Throughout the season we’ve got to keep getting better because we’re going to start playing better teams that can run the ball.”

Besieged by injuries to four defensive starters, the Packers retooled the nitro package in piecemeal fashion. They moved safety Morgan Burnett from inside linebacker to slot corner, something they practiced during the week. They brought Jones from the bench to inside linebacker alongside Martinez. And they counted on Marwin Evans to play safety alongside Ha Ha Clinton-Dix, even though Evans had played zero snaps from scrimmage all season.

The early results were rocky. After an 0-2 start, the Bengals fired their offensive coordinator and handed the job to quarterbacks coach Bill Lazor. His opening drive was scripted beautifully, blending five runs with five passes and gaining yards in chunks. A woeful offense came to life with a 10-play, 79-yard trek that ended with a touchdown for the first time this season.

They gained 5 or more yards on five of their first 10 snaps.

“Obviously, any time you have an unfamiliar opponent — with them being part of the AFC and having a new coordinator — you’re going to get unscouted looks,” outside linebacker Clay Matthews said. “They did a good job coming out on the first drive, assuming it was scripted, and kind of marching down the field. We didn’t do a good enough job of kind of weathering the storm so to speak during that first drive.”

Added outside linebacker Ahmad Brooks, who filled in for Perry: “The first half I didn’t feel too good about my performance. I felt like I was out of position on a few of those plays, I felt like I was on the ground way too much today. So there are things I need to clean up.”

Up front the Bengals folded several new wrinkles into their offense to ignite the running game, led by Mixon and complemented by running backs Jeremy Hill and Giovani Bernard. Nose tackle Kenny Clark said Lazor implemented more gap schemes and shotgun runs than the Packers had seen on tape, and the trio of tailbacks averaged 4.6 yards per carry in the first half.

From Hill they got a third-down conversion on a drive that ended in the end zone. From Bernard they got a 25-yard scamper and a 6-yard touchdown reception. And from Mixon they got flashes of the total package with nine plays of 5 yards or more.

“Oh, (Mixon) is a great back,” Martinez said. “He’s able to do it all, from catch out of the backfield, run down the middle, stretch you outside. He has everything in his game.

“I give him like two more years in that type of offense and how they use backs like him,” Jean Francois said. “That dude is going to be unreal when they can use that three-headed monster and he knows what he’s doing in the mix with everybody.”

The Bengals sputtered in the second half while protecting a surprising two-score lead. They gained 12 yards and punted; they gained 17 yards and missed a field goal; they gained 19 yards and punted again as the Packers came up with timely sacks on third down.

Nonetheless, the visitors were in position to sting the Packers and seal an impressive upset when their offense reclaimed the ball after a punt from Justin Vogel in the fourth quarter. They took the field with 9:43 remaining as Mixon again went to work.

After a defensive pass interference penalty moved the chains, Mixon ripped off three carries of 6 or more yards to drag the Bengals across midfield. He dodged defenders behind the line of scrimmage and hauled defenders for extra yards. He screamed every time his carries triggered a first down.

Sixty-four yards later, the nitro defense appeared ready to wilt as the clock melted below five minutes.

“If you look at the run game,” Matthews said, “I think it was guys not in their gap or not fitting correctly because for the most part it looked like they were bottled up. Obviously, with some scheme things they were putting some guys on the edge, some pullers and whatnot, putting big guys on small guys. Mixon (is) a big, hard back running strong for a rookie.”

It culminated with a third and 1 from the Green Bay 27-yard line as the clock approached four minutes. Again the Bengals turned to Mixon, only this time the rookie slipped to derail the play. Dalton couldn’t complete the handoff and was spun down for a short loss.

Mixon’s blunder forced the Bengals to settle for a field goal that pushed their lead to 24-17. The nitro package had been damaged, but the 7-point deficit meant Aaron Rodgers and the offense had a chance.

“That second half we just gave it our all to try to get back in that game,” Clark said. “I think we really picked it up.”